Photographic shutter.



W. TAYLOR.

` PHOTOGRAPHIG SHUTTER.

APPLICATION FILED 12h25, 1904.

908,355. Patented Deo. 29, 1908.l

2 SHBBTS-SHEET l.

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j zal 7H: Nnmws PETERS co., w'xsumswrr, o. c.

W. TAYLOR. PHOTOGRAPHIG SHUTTER.

APPLICATION FILED APR. 25. 1904.

908,355. Patented Dec. 29, 1908.

2 SHEETS-SHEET 2. 2 v

WILLIAM TAYLOR, OF LEICESTER, ENGLAND.

PHOTOGRAPHIC SHUTTER.

Specification of Letters Patent.

Patented Dec.A 29, 1908.

Application led April 25, 1904. Serial No. 204,826.

To all whom it may concern:

Be it known that i, TVLILLIAM TAYLOR, a subject oi' the King of Great Britain and Ireland, residing at Stoughton Street Vorks, Leicester, in the county of Leicester, England, have invented certain new and useful Improvements in Photographic Shutters, of which the following is a specification.

This invention relates to mechanism for operating the shutters of photographic cameras adapted either for time exposures, the duration oi which is determined by the actual manipulation of the operator, or for instantaneous exposures, the duration of which isdetermined by the actual manipulation of the operator, or for instantaneous exposures, the duration of which is automat ically governed.

The time of exposure of photographic shutters has been controlled in two ways, first by varying the rate of opening and closing, the second by opening and closing quickly and varying the time during which the shutter remains fully open. ln the latter class the time during whichthe shutter remains fully open is generally controlled by the escape of air into a pneumatic cylinder, and also in such cases the pneumatic cylinder is used as a butter to arrest the movement of the shutter when it opens and to delay its closing for a time which can be varied by varying the leakage of the pneumatic cylinder or by varying the amount of movement of its piston.

According to the present invention a spring separate from the motor spring is used to operate the timing device and the strength of this time spring may be adjusted so as to get a deiinite exposure for a given amount of movement of the pneumatic piston of the timing device. At the same time the timing piston is relieved of the shock due to arresting the motion of the shutter, and its motion being controlled more by leakage of the air and less by its elastic action, accurate timing of short intervals is thereby improved.

To improve further the accuracy of timing of short intervals, the pneumatic timing cylinder is arranged so that the movement of the piston tends to compress the air, and also the cylinder is made of variable capacity and is adjusted to have very small capacities for very short intervals.

The invention also includes an improved construction of shutter diaphragm and this, together with the improved motor, setting, releasing and timing mechanisms which cooperate to produce these results, are hereinafter more speciiically described with reference to the accompanying drawings in which- Figure 1 is a front elevation of the shutter; Fig. 2 is a back elevation with the cover and other parts removed to show the method of linking the diaphragm leaves; Fig. 3 is a section on line 3-3 of Fig. l, with parts omitted; Fig. 4 is a section at right angles to that of Fig. 3 showing the stop and bracket plates and the driving or motor part of the apparatus; Fig. 5 is a sectional plan showing practically all the various parts in proper relation, except the linkage between the motor part and the diaphragm, this being shown in plan in Fig. 6; Fig. is an end view of the hinge of the controlling gate and Figs. 7 and 7 other details hereinafter described, Figs. 3, 4, 5, 6, 6, 7 and 7iL being drawn to an enlarged scale.

The diaphragm of the shutter consists of a number of leaves ct connected by pivots al at one of their ends with the stop plate l) and equally spaced thereon. The front or aperture edges of the leaves are made with a reentrant angle so that each leaf constitutes two sides to the diaphragm aperture as shown in Fig. 1. The value oi the rentrant angle, if equal angles are used, is given by the expression rllX 180 where a is the number regular Octagon in two positions which may be equi-distant on either side from the normal aperture position.

Each of the leaves is linked to the two adjacent leaves by means of crossed links a2 pivoted one on either side of and equi-distant from the pivot a/ on which it turns, the said links having their ends connected one with another to form a closed series so that the motion imparted to one leaf is communicated equally and simultaneously to the others. The leaves are superimposed on each other in regular order on the flat stop plate b, which has a central aperture b and is arranged to fit inside the case so as to be rotatable therein about the common axis of the diaphragm and stop plate apertures.

The stop plate b has a number of fingers b2 which are slightly bent upwards to give them a spring action and which are adapted to engage under shoulders or ianges c on the bosses c of external adjusting dials, so that the dials may be assembled and held in place by inserting their bosses through holes in the case and turning the stop plate so that its fingers engage beneath the flanges.

The diaphragm is operated through a series of pivoted links so arranged that although the extent of the motion of one end of the series remains constant that of the other can be varied continuously from an equal amount down to as small an amount as may be desired. 1t is the latter end of the series which is pivotally connected with one of the leaves of the diaphragm while the former is connected with a part of the operating mechanism which has a constant range of motion. The motion is communicated from the operating mechanism or motor to one arm of a lever d, the other arm of which is connected through a pair of links e e with one of the leaves a of the diaphragm. The junction pivot of the links e e has one end of another link e2 pivoted thereon, the other end being pivoted on the outer end of an arm or sector plate f. The sector plate f is pivoted atfo at its center on and supported from a bracket g extending from the bracket or crown plate g and has a radial slot f in which engages a pin f 2 eccentrically mounted on a diskf3 which can be rotated on its central axis from outside the case by means of an adjustment dial f4. The slot is preferably formed with a narrow extensionf5 for the purpose of providing a spring action on the pin f 2 to take up wear of the parts in contact. On turning the dial f4 the eccentric pinf2 travels along the slot in the plate f which is thus rotated on its axis and therefore alters the position of the outer or fixed pivot of the link e2 about which as center the junction pivot of the three links rotates. The effect of varying the position of this point is to vary the direction of motion of the junction pivot of the three links, and thus to vary the ratio iof the motion transmitted through the links to that of the prime mover, and by this means the shutter can be set to open and close to any desired extent within the limits imposed by the a paratus.

Since one comp ete turn of the dial f4 will cause the plate f to move through its full range in both directions the two halves of the dial may be utilized for two separate scales of dierent values for use respectively with two lenses of correspondingly different focal lengths. A further adjustment of the aperture may be provided for by making the stop plate b rotatable within small limits, so that by turning it in one direction or the other, and with it the pivots of the diaphragm leaves, the aperture will be increased or diminished, since the point of the leaf to which the link e is pivoted is relatively a xed point.

rlhe operating motor is contained in a slotted tube or guideway r, which passes through holes in the rim of the case and is preferably held frictionally so as to be adjustable longitudinally and rotationally, but is finally secured in a fixed position therein. Projecting from one end of the tube is a push pin or push piece 7L by which the mechanism is set in motion, and which has a rib h extending through the slot r in the tube. The slot at this part is widened to allow partial rotation of the push rib, and the end of the slot is narrowed by an upward slope of the lower edge, so that when the push is returned to its normal longitudinal position along the tube by means of the returning spring h2 it is constrained also to return to a normal angular position. 'l his rotation might also be accomplished by torsional action of the spring.

Ns hen the push is pressed inwards it compresses the spring h2 and at the same time the rib h encounters a pin i projecting through the slot from one of a pair of pistons i, 7c working in the tube and which may be termed respectively the motor piece and the setting piece. rlhese pistons are urged away from each other by means of a compressed spring k3 to an extent which is limited by a link connecting the two. As shown in Fig. 5, this link is constituted by a pair of rods or wires i2 k2 extending inwardly from the pistons i k respectively, their inner ends about midway between said pistons being hook-shaped to engage one with the other as shown in Fig. 7. rl'he second piston 7c has also a pin c/ projecting through the slot r and adapted to engage with a stop Z on a controlling gate or controlling frame Z. Wl hen so engaged and the push h is pressed, the piston i is pushed forward and the spring h3 is further compressed between the pistons. As soon as the stop Z is made to release the pin c, the piston lc is driven forward by the compressed spring h3 through a definite distance which is determined as above described, at the same time compressing against a cap r2 on the further end of the tube another and weaker spring h4, which serves afterward to return the pistons to their normal positions. There is a transverse slot 7c3 in the piston 7c in which engages a pin d which projects from the lever d through an opening in the tube r, and by which motion is transmitted to the shutter.

The controlling gate l may be arranged to slide in a suitable guide, but is preferably mounted on hinges, the axis of which is parallel to the tube r, and is urged by a spring Z2 so that when the push is in the idle or starting position a projecting wing Z3 on the gate bears gently down on the pin i of the piston fi while the stop Z is in position, justin front of the pin ZC of the piston Zr. TWhen the push is pressed the pin Ze is urged to over ride the stop Z', the two being suitably shaped for this object as shown in Fig. 7 a, and therefore to depress the gate. This, however, is prevented by the wing Z3 of the gate bearing on the pin i until the latter has been moved along by the push ZL under the wing Z3 so as to clear it. The pin Zc then opens the gate and escapes from the stop, and the piston Zr makes its outward movement and opens the shutter. The wing Z3 of the gate now engages behind the pin i and obstructs its return, but the rib ZL of the push pin, having been depressed by the wing of the gate, is no longer in position to obstruct the pin i and may be released, when it will be returned by the spring Zi2 to its normal position. lhen the push is again pressed, the rib Zt which on the first occasion passed over a spring urged catch piece, which may be the free end of a wire spring h5, is now deflected by the wing Z3 to pass under the catch piece. The rib Zi in passing under the catch piece wedges it up against the wing of the controlling gate, which is therefore raised, thereby freeing the pin i and allowing the spring h4 to return both pistons together to their normal or starting position and thus closing the shutter.

The pivots Z*t on which the controlling gate is hinged, are held in V-shaped channels or grooves in the spring plates Z5 against the surface of flat plates Zs as shown in Fig. 6, the ends of the pivots projecting beyond the ends of the plates. This construction enables the pivots to slide along their bearings for the purpose of admitting the controlling gate which is pivoted on the two inner ends, and also a second frame m which is hinged on the outer ends of the pivots, and is preferably balanced about its pivot axis by means of a suitable counterpoisem5,

One end of a spring m is fixed to the frame m by a set screw m2, by means of wnich the set of the spring may be adjusted, while the other end which is free, extends towards the piston ZC and is bent down so as to engage with and be raised by the pin 7c when it is driven forward as above described. The frame m is thus turned on its hinges and brings the end of a finger m3 on the opposite side of the hinges downwards on the end of a piston n of a constant leakage pneumatic cylinder n. Vhen the piston has been depressed by this finger to nearly the end of its range, an adjustable screw stop m4 in the frame encounters a rearward projection Z7 of the controlling gate situated on the same side of the common axis of the two parts and depresses it, thus raising the wing Z3 of the gate, the edge of which acts as a stop for the piston i, when the shutter is o en, and thereby allowing the pistons to e instantaneously returned to their starting position and the shutter closed.

The pneumatic piston n is returned to its starting position by means of a light coiled spring n2 conveniently placed inside the piston which is made hollow to receive it. A pin n3 projecting` from the piston is arranged to move in vertical guides n4 attached to the cylinder n, and is pressedl upwards by the spring a2 against a cam surface a5 encircling the piston. By rotating a dial n situated outside the case and attached to the cylinder n, the piston is also rotated and the pin n3 traverses the cam surface. By this means the piston can be made to project more or less from the cylinder and thus its range of motion varied. The more the piston projects the earlier does the finger m3 of the hinged frame come into contact with it, and therefore the longer is the time before the frame reaches the position at which it actuates the controlling gate.

The capacity of the cylinder may be reduced and its action rendered more certain, especially for the shorter exposures, by inclosing within the hollow timing piston and within the spring a2 a core piece a7 secured to the cylinder cap, the arrangement being such that the air capacity of the cylinder is a minimum when the device is set for timing the shortest exposure, and increases forincreased time of action.

By means of a scale on the dial the neumatic retarding or timing device may e set to give any required exposure in automatic working of the shutter. Another cam 0 having a dial o projecting outside the case is provided as a stop by which the hinged frame may be rendered inoperative when the shutter is to be used for handl or time exposures.

The cam o may conveniently be formed on the leaky cylinder of a pneumatic check, the piston of which is pressed upwards by a light spring against the hinged frame mi This arrangement serves both to control the impact of the finger m3 with the timing piston and also to return and hold the frame and the check in a fixed starting position.

The spring m on the hinged frame, in addition to performing the function already described, by its pressure on the pin Zc of the piston Zr prevents the latter from being brought up at the end of its stroke with a jar or shock, andl thus prevents jumping of the shutter.' The adjusting set screw m2 on this spring may also be used for adjustment in conjunction with the pneumatic timing piston. 1t may, for example, be used to adjust the time required for the motion of the piston through its extreme range to some dennite amount, say one second. For an exposure of 1/50th of a second, the timing piston might be set in its lowest operative position, and the adjustment made by means of the adjustable screw stop m4 in the hinged frame m. Intermediate exposures would then be determined by the position of the pneumatic timing piston, and a timing dial scale constructed accordingly.

In addition to the various adjustments already set forth, means is also provided for adjusting the axis of the junction pivot of the links e, e, e2, to coincide with the axis of the sector plate f. This is done by placing the fulcrum pivot of the lever d on a bar p having forked ends p which are clamped under pillars p2 to the crown plate. The movement permitted by the forked ends of the bar when unclamped enables the junction pivot of the links e, e, e2, to be adjusted as may be required.

The adjustment of the tube r may be provided for by means of a dowel plate q adjustably clamped to the case by means of a screw pillar q, and having dowels g2 fitting in recesses in the wall of the tube r.

The operation of the various parts of the mechanism has been fully described in connection with these several parts, but the operation of the apparatus as a whole may be briel'ly stated as follows: The apparatus may be used either for timed exposures or for so-called instantaneous exposures. In the former case the dial 0l is turned to the position in which it renders the hinged frame m inoperative. On pressing the push ZL once, the spring between the two pistons, that is between the motor piece and setting piece, is compressed and the pin ZC on the piston Zc thus urged to override the stop Z on the controlling gate Z, which, however, it is prevented from doing until the pin i has been moved by the push ZL clear oi' the wing Z3 on the starting gate, whereupon the piston Zc is shot forward through a deiinite distance, and by means of the linkage previously described opens the leaves of the diaphragm. The return of the pistons is prevented by the engagement ofthe wing of the controlling gate in rear of the pin i until on releasing the push ZL and pressing it again, the catch piece h5 is urged by the rib ZL of the push to lift the wing of the controlling gate,

thus freeing the pistons and enabling them to be returned to their starting positions by the spring Zvi, and the leaves of the diaphragm close.

When the shutter is to be used for instantaneous or automatic exposures the dial 0 is turned to free the hinged frame m and the seconds dial n turned to give the required exposure. Pressing the push ZL once operates as already explained to open the diaphragm, the parts being then left in such a position that the shutter remains open.

In this case, however, the forward movement of the piston ,7c to open the shutter has actuated the hinged frame m so that when, after a time determined by the setting of the retarding device n, the adjustable screw stop m4 on the frame engages the controlling gate and depresses it to raise the wing Z3, the pistons i, 7c are thereby automatically released and the shutter closed.

I-Iaving thus described the nature of this invention and the best means I know of carrying the same into practical e'fl'ect, I claim:-

1. Apparatus for operating photographic shutters comprising a driving spring for opening the shutter, a detent for holding it open, mechanism operating to withdraw said detent, and a second spring separate from the driving spring and set in operation upon the shutter being opened, to actuate the said mechanism, substantially as described.

2. Apparatus for operating photographic shutters, comprising a driving spring, mechanism actuated thereby to open the shutter, a detent adapted to-hold the shutter open, mechanism operating to withdraw said detent, and a second spring separate from the driving spring operating to actuate said mechanism, said second spring and detent being made operative upon the opening of the shutter, substantially as described.

3. Apparatus for operating photographic shutters, comprising a driving spring, a motor piece actuated thereby, a setting piece, a detent controlling said motor piece and setting piece, means 'for setting the said driving spring, and means operating as soon as the setting of the driving spring is completed to displace the said detent to release the motor piece and lock the setting piece, substantially as described.

4. Apparatus for operating photographic shutters, comprising a push piece, a guide way, a setting piece and a motor piece movable in said guideway, said. setting piece being adapted to be displaced by the push piece, a link connecting said setting piece and motor piece to limit their relative displacement, a driving spring adapted to be set by the displacement of the setting piece, and means 'for locking the setting piece and releasing the motor piece, substantially as described.

5. Apparatus for operating photographic shutters, comprising a motor piece, a manually operated setting piece linked to said motor piece, a driving spring interposed between the said motor and setting pieces, means preventing the movement of the motor piece during the setting movement of the setting piece, means preventing the return of the setting and motor pieces, and means controlling the release of the said pieces substantially as described.

6. Apparatus for actuating photographic shutters, comprisinfr a setting piece and a motor piece movable in guides, a link connecting said motor and setting pieces to limit their relative displacement, a compression spring between said motor and setting pieces, means for advancing the setting piece to further compress the said spring, a detent placed to hold the motor piece during said movement of the setting piece, and means for returning the setting and motor pieces to their normal positions, substantially as described.

7. Apparatus for actuating photographic shutters, comprising a push piece, a setting iece, a motor piece, and a pivoted controling iframe having projections cooperating with the said push piece, setting piece and motor piece, substantially as described.

8. 1n apparatus of the character herein described, a releasing spring set upon opening the shutter, a pivoted controlling gate operating to prevent closure of the shutter, and a pivoted frame reacted upon by the said spring to displace said controlling gate, and release the shutter, substantially as described.

9. In apparatus of the character herein described, a releasing spring set upon opening the shutter, a pivoted controlling gate operating to prevent closure orp the shutter, a pivoted frame reacted upon by the said s ring to displace the controlling gate and re ease the shutter, and an adjustable retarding device co'o'perating with the said pivoted 'frame to vary the interval elapsing between the opening of the shutter and its release, substantially as described.

10. ln apparatus of the character herein described, a pneumatic timing device for determining the eriod during which the shutter remains iullly open, comprising a leaky cylinder, a piston movable therein under the action o1E the shutter releasing mechanism to compress the air Within the cylinder, means Jfor reducing the impact of the shutter releasing mechanism with the movable iston and means for varying the capacity cip the cylinder, substantially as described.

11. ln apparatus of the character herein described, a detent operating to prevent closure of the shutter, a movable 'frame operating to displace said detent, a retarding device cooperating with said frame, and a pneumatic check operating to reduce the impact of the said movable trame with the said retarding device, substantially as described.

12. 1n apparatus of the character herein described, a setting piece, a push piece adapted to displace the setting piece longitudinally, a detent adapted to prevent the return of the said setting piece and to displace the said push piece rotationally, and a spring catch piece cooperating with the said push piece to displace the detent and release the setting piece, substantially as described.

13. In apparatus of the character herein described, a setting piece and a motor piece, a link connecting said pieces to limit their distance apart, a s ring operating to keep said pieces at a like distance apart, a second spring set by the movement of the motor piece and operating to return said motor piece and setting piece to normal positions, substantially as described.

14. 1n apparatus of the character herein described, a setting iece, a push piece adapted to displace said setting piece longitudinally, and means operating to deflect the said push piece out of the return path of the setting piece, substantially as described.

15. In apparatus of the character herein described, a push piece, a guide way constraining the movement of said ush piece, said guideway being formed to a low partial rotation of said push piece, and means operating to return said push piece to its starting position in the guideway, substantially as described.

16. In apparatus of the character herein described, a casing, a guide tube adjustably secured in said casing, and a push piece, a setting piece, a motor piece, and cooperating springs all contained within said guide tube, substantially as described.

17. In apparatus of the character herein described, a diaphragm comprising a plurality of pivoted leaves, each formed on its inner edge with a rentrant angle to contribute two sides to the diaphragm aperture, and a closed series of links connecting said leaves to move them simultaneously, substantially as described.

18. 1n apparatus of the character herein described, motor mechanism, a diaphragm, a pair of links connecting said diaphragm with the motor mechanism, and means for directing the motion of the junction pivot of said pair of links, substantially as described.

19. 1n apparatus of the character herein described, motor mechanism, a diaphragm, a pair of links connecting said diaphragm with the motor mechanism, a third link pivoted at one end on the said pair of links at their junction pivot, and means for varying the position of the other end of the third link, substantially as described.

20. 1n apparatus of the character herein described, a diaphragm, a motor piece, a pair of links pivoted together and connecting the diaphragm with said motor piece, an arm pivotally mounted in the frame coaXially with the junction pivot of the said pair of links when the shutter is closed, a third link having one end pivoted eccentrically on said arm and its other end pivoted to the pair f links coaxially with their junction pivot, and means for rocking said arm about its pivot axis, substantially as described.

21. In apparatus of the character herein described, a retarding device operating to vary the time during which the shutter re- In testimony whereof L' have signed my mains fully open, comprising a constant name to this specification in the presence of leakage pneumatic cylinder, a hollow iston tWo subscribing Witnesses. operating to compress the air in the ey index' WILLIAM TAYLOR.

' during the Working stroke, and a core piece Witnesses:

Within the said cylinder adated to Vary the A. PIERCE, capacity thereof, substantie y as described. H. PETTY. 

